A SiMplified bARe-Wire Target Vessel (SMART) Technique for Fenestrated Endovascular Aortic Repair

PURPOSE

The aim of this study was to present a new technique for fenestrated endovascular aortic aneurysm repair (FEVAR) and to review its preliminary results. The SiMplified bARe-wire Target vessel (SMART) technique for FEVAR aims to simplify the procedure by avoiding guiding sheaths into visceral arteries during the main graft deployment.

MATERIALS AND METHODS

The SMART technique requires a 12 to 16Fr contralateral introducer, depending on number of fenestrations-compared with standard 18 to 22Fr for 3 to 4 FEVAR-to achieve target vessel catheterization and stenting during FEVAR by avoiding the use of parallel 6 to 7Fr guiding sheaths into each visceral vessel. Fenestrations are sequentially catheterized, assisted by a steerable sheath. A Rosen wire is maintained in each fenestration, with a single sheath parked in the final target vessel while releasing the fenestrated graft. Data on patients treated for pararenal or thoracoabdominal aortic aneurysms with FEVAR, adopting the SMART technique, were retrospectively reviewed. End points were technical success, intraprocedural variables, 90-day mortality, major adverse events (MAEs), and target vessel patency.

RESULTS

From May 2018 to December 2020, 57 consecutive patients were treated for pararenal or thoracoabdominal aortic aneurysms. Median total procedure time and total fluoroscopy time were 223 (196-271) minutes and 81 (71-94) minutes, respectively. Primary technical success was 96.4% (55/57). No misalignment occurred from graft deployment. The total number of fenestrations was 169, including 54 left and 53 right renal arteries, 43 superior mesenteric arteries and 18 celiac trunks (3.0±0.9 vessels/patient), with target vessel technical success of 98.2%. During the first 90 days, there were no deaths (0%). The MAEs included acute kidney injury (AKI) in 3 patients (5%) with no new dialysis onset, respiratory failure requiring prolonged ventilation in 2 patients (4%), myocardial ischemia in 1 patient (2%), but no lower limb ischemia, stroke, or spinal cord ischemia (SCI) occurred. After a mean follow-up of 14±10 months, there was 1 aortic-related death. Primary and assisted primary target vessel patency was 94.6%±1.8 and 97.0%±1.3% respectively.

CONCLUSIONS

The SMART technique proved to be a safe alternative to standard FEVARs, with excellent technical result and acceptable target vessel patency at mid-term, while reducing the risk for introducer-induced lower limb ischemia, related complications, and morbidity.

CLINICAL IMPACT

This study evalautes the outcome of fenestrated endovascular aortic repair (FEVAR) procedures at Uppsala university hospital using a simplified bare-wire Target vessel (SMART) technique. The SMART technique requires a smaller contralateral introducer compared to standard 18-22Fr for 3-4 FEVAR to achieve target vessel catetherization and stenting. Fifty-seven consecutive patients were treated for pararenal or thoracoabdominal aortic aneurysms. The SMART technique proved to be a safe alternative to standard FEVARs with excellent technical result and acceptable target vessel patency at mid-term, while reducing the risk for introducer-induced lower limb ischemia, related complications, and morbidity.

Post-Operative and Mid-Term Renal Function Impairment Following Elective Fenestrated Endovascular Aortic Repair for Complex Aortic Aneurysms: Incidence and Risk Factors Analysis

Background. The aim of this study was to assess the incidence of two post-operative acute kidney injury (AKI) stages according to the Risk, Injury, Failure, Loss of function, End-stage (RIFLE) criteria in patients undergoing fenestrated endovascular aortic repair (FEVAR) for complex aortic aneurysms. Furthermore, we analyzed predictors of post-operative AKI and mid-term renal function deterioration and mortality. Methods. We included all patients who underwent elective FEVAR for abdominal and thoracoabdominal aortic aneurysms between January 2014 and September 2021, independently from their preoperative renal function. We registered cases of post-operative acute kidney injury (AKI) both at risk (R-AKI) and injury stage (I-AKI) according to the RIFLE criteria. Estimated glomerular filtration rate (eGFR) was noted preoperatively, at the 48th post-operative hour, at the maximum post-operative peak, at discharge, and then during follow-up approximately every six months. Predictors of AKI were analyzed with univariate and multivariate logistic regression models. Predictors of mid-term chronic kidney disease (CKD) (stage ≥ 3) onset and mortality were analyzed using univariate and multivariate Cox proportional hazard models. Results. Forty-five patients were included in the present study. Mean age was 73.9 ± 6.1 years and 91% of patients were males. Thirteen patients (29%) presented with a preoperative CKD (stage ≥ 3). Post-operative I-AKI was detected in five patients (11.1%). The aneurysm diameter, thoracoabdominal aneurysms and chronic obstructive pulmonary disease were identified as predictors of AKI in univariate analysis (OR 1.05, 95% CI [1.005-1.20], p = 0.030; OR 6.25, 95% CI [1.03-43.97], p = 0.046; OR 7.43, 95% CI [1.20-53.36], p = 0.031; respectively), yet none of these factors were significative on multivariate analysis. Predictors of CKD onset (stage ≥3) during follow-up on multivariate analysis were age (HR 1.16, 95% CI [1.02-1.34], p = 0.023), post-operative I-AKI (HR 26.82, 95% CI [4.18-218.10], p < 0.001) and renal artery occlusion (HR 29.87, 95% CI [2.33-309.05], p = 0.013), while aortic-related reinterventions where not significantly associated with this outcome in univariate analysis (HR 0.66, 95% CI [0.07-2.77], p = 0.615). Mortality was influenced by preoperative CKD (stage ≥3) (HR 5.68, 95% CI [1.63-21.80], p = 0.006) and post-operative AKI (HR 11.60, 95% CI [1.70-97.51], p = 0.012). R-AKI did not represent a risk factor for CKD (stage ≥ 3) onset (HR 1.35, 95% CI [0.45-3.84], p = 0.569) or for mortality (HR 1.60, 95% CI [0.59-4.19], p = 0.339) during follow-up. Conclusions. In-hospital post-operative I-AKI represented the main major adverse event in our cohort, influencing CKD (≥ stage 3) onset and mortality during follow-up, which were not influenced by post-operative R-AKI and aortic-related reinterventions.

Chimney Versus Fenestrated Endovascular Versus Open Repair for Juxta/Pararenal Abdominal Aortic Aneurysms: Systematic Review and Network Meta-analysis of the Short-term Results

INTRODUCTION

The aim of this systematic review and network meta-analysis was to compare the short-term results of fenestrated endovascular repair (FEVAR), chimney endovascular repair (ChEVAR), and open surgery (OS) for patients with juxta/pararenal abdominal aortic aneurysms (JAAA/PAAA).

MATERIALS AND METHODS

MEDLINE, SCOPUS, and Web of Science were searched from inception to 1 July 2022. Any comparative studies investigating the results of two or three treatment strategies (ChEVAR, FEVAR, or OS) on clinical outcomes for patients with JAAA/PAAA were included. Analysed outcomes were 30-day mortality, acute kidney injury (AKI), major adverse cardiovascular events (MACE), and bowel ischaemia (BI).

RESULTS

A total of 22 studies with 8853 patients were included in the analysis. FEVAR (OR = 0.58, 95%CrI 0.36-0.82) and ChEVAR (OR = 0.56, 95%CrI 0.28-1.02) were associated with lower 30-day mortality than OS. FEVAR (OR = 0.54, 95%CrI 0.33-0.85) was associated with lower risk of AKI than OS. FEVAR (OR = 0.43, 95%CrI 0.20-0.89) and ChEVAR (OR = 0.34, 95%CrI 0.10-0.93) compared to OS were associated with lower rates of BI. FEVAR (OR = 0.67, 95%CrI 0.49-0.90) and ChEVAR (OR = 0.61, 95%CrI 0.35-1.02) were associated with lower 30-day MACE risk than OS. FEVAR was associated with a higher rate of SCI compared to OS (OR = 4.90, 95%CrI 1.55-19.17).

CONCLUSION

We found a clear benefit for FEVAR and ChEVAR versus OS in terms of reduced 30-day mortality, BI, and MACE, as well as AKI for FEVAR. This suggests that higher-risk patients might benefit from endovascular treatment of JAAA/PAAA; however, should be applied in clinical practice with caution, since long-term outcomes were outside of the scope of this review.

Comparative Effectiveness of Treatment Modalities for Complex Aortic Aneurysms: A Network Meta-Analysis of Observational Studies

BACKGROUND

To conduct a network meta-analysis comparing multiple treatments for complex aortic aneurysms (CAAs).

METHODS

Medical databases were searched on November 11, 2022. Twenty-five studies (5,149 patients) and four treatments (open surgery [OS], chimney/snorkel endovascular aneurysm repair [CEVAR], fenestrated endovascular aneurysm repair [FEVAR], and branched endovascular aneurysm repair) were selected. Outcomes were branch vessel patency, mortality, and reintervention at short- and long-term followup, and perioperative complications.

RESULTS

Regarding branch vessel patency, OS was the most effective treatment and had higher 24-month branch vessel patency rates than CEVAR (odds ratio [OR], 10.77; 95% confidence interval [CI], 2.08-55.79). FEVAR (OR, 0.52; 95% CI, 0.27-1.00) and OS (OR, 0.39; 95% CI, 0.17-0.93) were better than CEVAR regarding 30-day mortality and 24-month mortality, respectively. Regarding 24-month reintervention, OS was better than CEVAR (OR, 3.07; 95% CI, 1.15-8.18) and FEVAR (OR, 2.48; 95% CI, 1.08-5.73). Regarding perioperative complications, FEVAR had lower acute renal failure rates than OS (OR, 0.42; 95% CI, 0.27-0.66) and CEVAR (OR, 0.47; 95% CI, 0.25-0.92) and lower myocardial infarction rates than OS (OR, 0.49; 95% CI, 0.25-0.97) and was the most effective treatment in preventing acute renal failure, myocardial infarction, bowel ischemia, and stroke, while OS was the most effective treatment in preventing spinal cord ischemia.

CONCLUSIONS

OS might have advantages regarding branch vessel patency, 24-month mortality, and reintervention and is similar to FEVAR regarding 30-day mortality. Regarding perioperative complications, FEVAR might confer advantages in preventing acute renal failure, myocardial infarction, bowel ischemia, and stroke, and OS in preventing spinal cord ischemia.

Chimney vs. Fenestrated Endovascular vs. Open Repair for Juxta/Pararenal Abdominal Aortic Aneurysms: Systematic Review and Network Meta-Analysis of the Medium-Term Results

Introduction: This systematic review with network meta-analysis aimed at comparing the medium-term results of open surgery (OS), fenestrated endovascular repair (FEVAR), and chimney endovascular repair (ChEVAR) in patients with juxta/pararenal abdominal aortic aneurysms (JAAAs/PAAAs). Materials and methods: MEDLINE, SCOPUS, and Web of Science were searched from inception date to 1st July 2022. Any studies comparing the results of two or three treatment strategies (ChEVAR, FEVAR, or OS) on medium-term outcomes in patients with JAAAs/PAAAs were included. Primary outcomes were all-cause mortality, aortic-related reintervention, and aortic-related mortality, while secondary outcomes were visceral stent/bypass occlusion/occlusion, major adverse cardiovascular events (MACEs), new onset renal replacement therapy (RRT), total endoleaks, and type I/III endoleak. Results: FEVAR (OR = 1.53, 95%CrI 1.03-2.11) was associated with higher medium-term all-cause mortality than OS. Sensitivity analysis including only studies that analysed JAAA showed that FEVAR (OR = 1.65, 95%CrI 1.08-2.33) persisted to be associated with higher medium-term mortality than OS. Both FEVAR (OR = 8.32, 95%CrI 3.80-27.16) and ChEVAR (OR = 5.95, 95%CrI 2.23-20.18) were associated with a higher aortic-related reintervention rate than OS. No difference between different treatment options was found in terms of aortic-related mortality. FEVAR (OR = 13.13, 95%CrI 2.70-105.2) and ChEVAR (OR = 16.82, 95%CrI 2.79-176.7) were associated with a higher rate of medium-term visceral branch occlusion/stenosis compared to OS; however, there was no difference found between FEVAR and ChEVAR. Conclusions: An advantage of OS compared to FEVAR and ChEVAR after mid-term follow-up aortic-related intervention and vessel branch/bypass stenosis/occlusion was found. This suggests that younger, low-surgical-risk patients might benefit from open surgery of JAAA/PAAA as a first approach.

Endovascular Repair Versus Open Surgical Repair for Complex Abdominal Aortic Aneurysms: A Systematic Review and Meta-analysis

OBJECTIVE

The purpose of this systematic review and meta-analysis was to compare the short and long-term outcomes of endovascular repair (ER) versus open surgical repair (OSR) for complex abdominal aortic aneurysms (CAAAs), using propensity-matched and non-propensity-matched methods.

METHODS

PubMed, OVID, Embase, ELSEVIER and Cochrane library were searched for the studies that compared ER versus OSR for CAAAs from January 1999 to December 2020. CAAAs were defined as short neck, juxtarenal, pararenal and suprarenal abdominal aortic aneurysms. The primary outcomes were 30-day mortality, 30-day reintervention, medium and long-term survival. We pooled outcomes of original studies and also performed subgroup analyses using RevMan. The analysis of statistical heterogeneity was performed with STATA 16.0.

RESULTS

21 studies with 12049 patients (3847 ERs, 8202 OSRs) were included in this meta-analysis. In general, the patients undergoing ER were significantly older and likely to be man; more common with diabetes mellitus, congestive heart failure, renal failure, but smaller aortic aneurysms. In the non-propensity-matched subgroup analysis of ER versus OSR, ER was associated with significantly decreased 30-day mortality (odds ratio [OR]: 0.60; 95% confidence interval [CI]: 0.49-0.74; P＜.001; I²=4%) and 30-day reintervention (OR: 0.59; 95% CI: 0.40-0.87; P = .007; I²=56%); lower rate of long-term survival (hazard ratio [HR]: 1.73; 95% CI: 1.21-2.47; P = .002; I²=0%); less perioperative comorbidities including myocardial infarction, arrhythmia, acute kidney injury, permanent dialysis, wound complications, bowel ischemia; and shorter hospital length of stay. In the propensity-matched subgroup, ER was associated with poorer long-term survival (HR: 1.80; 95% CI: 1.06-3.06; P = .03; I²=0%), higher incidences of lower extremity ischemia (OR: 12.25; 95% CI: 1.54-97.48; P = .02; I²=16%) and renal artery restenosis (OR: 7.63; 95% CI: 1.35-43.24; P = .02). However, there was no significant difference in 30-day mortality (OR: 1.31; 95% CI: 0.65-2.66; P = .45; I²=0%), 30-day reintervention (OR: 1.58; 95% CI: 0.62-4.03; P = .34; I²=26%), mid-term survival (HR: 1.03; 95% CI: 0.30-3.56; P = .96; I²=0%) between ER and OSR groups.

CONCLUSION

Our analyses suggest that OSR of CAAAs, compared with ER, is associated with improved long-term survival without increasing of perioperative deaths. ER may be considered in the patients who are high-risk for open repair.

Editor's Choice - Comparison of Open, Standard, and Complex Endovascular Aortic Repair Treatments for Juxtarenal/Short Neck Aneurysms: A Systematic Review and Network Meta-Analysis

OBJECTIVE

Abdominal aortic aneurysms (AAAs) with adverse morphology of the aneurysm neck are "complex". Techniques employed to repair complex aneurysms include open surgical repair (OSR) and a number of on label endovascular techniques such as fenestrated endovascular aneurysm repair (FEVAR) and endovascular aneurysm repair (EVAR) with adjuncts (including chimneys and endo-anchors), as well as off label use of standard EVAR. The aim was to conduct a network meta-analysis (NMA) of published comparative outcomes.

DATA SOURCES

An electronic search was performed in Embase, MEDLINE, and the Cochrane Central Register of Controlled Trials (CENTRAL). These databases were interrogated using the PubMed interface and the Healthcare Databases Advanced Search (HDAS) interface developed by the National Institute of Health and Care Excellence.

REVIEW METHODS

Online databases were interrogated up to April 2020. Studies were included if they compared outcomes between at least two methods of repair for complex aneurysms (those with at least one adverse neck feature: absent/short neck, conicality, angulation, calcification, large diameter, and thrombus). The primary outcome measure was peri-operative death. Pre-registration was done in PROSPERO (CRD42020177482).

RESULTS

The search identified 24 observational studies and 7854 patients who underwent OSR, FEVAR, off label EVAR, or chimney EVAR. No comparative studies included EVAR with endo-anchors. NMA was performed on 23 studies that reported outcomes of aneurysms with short/absent infrarenal neck. Compared with OSR, off label EVAR (relative risk [RR] 0.10, 95% confidence interval [CI] 0.01 - 0.41) and FEVAR (RR 0.62, 95% CI 0.32-0.94) were associated with lower peri-operative mortality. This difference was not seen at the midterm follow up (30 months). Compared with OSR, FEVAR was associated with a lower peri-operative myocardial infarction (MI) rate (RR 0.37, 95% CI 0.16 - 0.62) but a higher midterm re-intervention rate (hazard ratio 1.65, 95% CI 1.04 - 2.66). All studies had a "moderate" or "high" risk of bias. Confidence in the network findings (GRADE) was generally "low".

CONCLUSION

This NMA demonstrated a peri-operative survival benefit for off label EVAR and FEVAR compared with OSR, potentially due to reduced risk of MI. FEVAR carries a greater midterm re-intervention risk than OSR, with potential implications for cost effectiveness. There is paucity of comparative data for cases with adverse neck features other than short length.

Diseases of the Aorta and Kidney Disease: Conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

Chronic kidney disease (CKD) is an independent risk factor for the development of abdominal aortic aneurysm (AAA), as well as for cardiovascular and renal events and all-cause mortality following surgery for AAA or thoracic aortic dissection. In addition, the incidence of acute kidney injury (AKI) after any aortic surgery is particularly high, and this AKI per se is independently associated with future cardiovascular events and mortality. On the other hand, both development of AKI after surgery and the long-term evolution of kidney function differ significantly depending on the type of AAA intervention (open surgery vs. the various subtypes of endovascular repair). Current knowledge regarding AAA in the general population may not be always applicable to CKD patients, as they have a high prevalence of co-morbid conditions and an elevated risk for periprocedural complications. This summary of a Kidney Disease: Improving Global Outcomes Controversies Conference group discussion reviews the epidemiology, pathophysiology, diagnosis, and treatment of Diseases of the Aorta in CKD and identifies knowledge gaps, areas of controversy, and priorities for future research.

Incidence and predictors of early and delayed renal function decline after aortic aneurysm repair in the Vascular Quality Initiative database

BACKGROUND

Postoperative acute kidney injury (AKI) may complicate both open and endovascular aortic aneurysm repair (EVAR) and is associated with substantial morbidity, mortality, and health care expense. We aim to evaluate the incidence of postoperative AKI and factors associated with its occurrence and the effects of postoperative AKI on long-term renal function and mortality after open and EVAR in the Society for Vascular Surgery Vascular Quality Initiative registry.

METHODS

Elective aneurysm cases were identified including thoracic endovascular aortic aneurysm repair (TEVAR) and complex endovascular aortic aneurysm repair (cEVAR), infrarenal endovascular repair (EVAR) and infrarenal open repair (OAR) from 2003 to 2019. The preoperative estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease formula and stratified based on chronic kidney disease (CKD) grades. Postoperative AKI was defined per the Vascular Quality Initiative definition as a creatinine increase of 0.5 mg/dL or if postoperative dialysis was required. Patients on preprocedural hemodialysis and those with previous renal transplant were excluded. Demographics and procedural factors were evaluated for predicting in-hospital postoperative AKI (all approaches) and at 9 to 21 months of long-term follow-up (EVAR only) using logistic regression modeling.

RESULTS

We identified a total of 2813 cEVAR, 2995 TEVAR, 39,945 EVAR, and 8143 OAR patients. Of those, postoperative AKI occurred in 377 cEVAR (13.5%), 199 TEVAR (6.7%), 1099 EVAR (2.8%), and 1249 OAR (15.5%). Risk factors for postoperative AKI across all groups were worse preoperative eGFR, total number of blood transfusions, perioperative anemia, reinterventions, and postoperative respiratory complications. Additional procedure-specific risk factors of postoperative AKI were preoperative hemoglobin of less than 10 and contrast volume of 125 to 150 mL, hypertension, a low ejection fraction, and a history of percutaneous revascularization for EVAR; for both EVAR/cEVAR, renal artery coverage was a risk factor, whereas for OAR, male sex, non-White race, hypertension, suprarenal aortic cross-clamp, and increased renal ischemic time were risk factors. Among 8133 EVAR patients with long-term follow-up, a decrease in kidney function occurred in 56.7% of patients with postoperative AKI vs 19.9% without postoperative AKI (P < .001). The following risk factors were associated with a decrease in renal function at long-term follow-up: postoperative AKI, a preoperative eGFR of less than 90, and hypertension. A preoperative hemoglobin of greater than 12 was protective. Postoperative AKI was associated with significantly lower survival compared with no postoperative AKI across all procedures (log rank <0.001).

CONCLUSIONS

Postoperative AKI occurs more often in patients with worse preoperative renal function, lower preoperative hemoglobin, and in open surgeries with inter-renal or suprarenal cross-clamping. Importantly, postoperative AKI is associated with increased mortality across all types of aortic repair. Given the long-term impact of postoperative AKI on outcomes for all aortic repairs and the limitations of current insensitive functional indices, there is a need to seek more sensitive indicators of decreases in early renal structural in this population.

The role of fEVAR, chEVAR and open repair in treatment of juxtarenal aneurysms: a systematic review

INTRODUCTION

Open repair (OR), fenestrated endovascular aneurysm repair (fEVAR) and endovascular exclusion using parallel graft (chEVAR) are complementary procedures used for treatment of juxtarenal abdominal aortic aneurysm (jrAAA). The aim of our study was to assess available literature and analyze dispersion of OR, fEVAR and chEVAR procedures among reported papers related to treatment of jrAAA.

EVIDENCE ACQUISITION

The PubMed database was systematically searched using predefined strategy and key words related to treatment of jrAAA on September 28th, 2019. Studies were assessed for eligibility using the inclusion and exclusion criteria with at least five patients treated with at least one of the procedures while systematic reviews, meta-analysis, reviews, comments, editorials and letters were excluded as well as studies without clear classification of the location of the aneurysm, studies not specifying the number of patients treated with each of the techniques or not discriminated between aortic pathologies (juxtarenal, paravisceral and thoracoabdominal), hybrid procedures, endoanchors or with branched stent-graft.

EVIDENCE SYNTHESIS

Overall, 1533 papers were identified while papers that met inclusion criteria were either representing experience of single institution (87 papers) or from multicenter studies (6 papers), national or international registries (18 papers). In the period between January 1977 and December 2017, treatment of 5664 patients with jrAAA was reported in 87 papers as a single institution report. Out of them 2531 (45%) were treated with OR, 2592 (46%) with fEVAR and 541 (9%) with chEVAR. Out of 29 institutions reporting OR, there were 11 (37.9%) with more than 100 treated patients while 21 (41.1%) out of 51 institutions that reported more than 50 jrAAA treated with fEVAR. Only four institutions reported results of all three treatment modalities.

CONCLUSIONS

Based on the results reported in the literature, regardless of its complexity and costs, fEVAR for jrAAA has been accepted in substantial number of hospitals worldwide, while number of reported procedures is reaching OR.

The Clinical Utility and Assessment of Renal Biomarkers in Acute Kidney Injury After Abdominal Endovascular Aneurysm Repair. A Systematic Review

The widespread adoption of endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAA) is due to the obvious advantages of the procedure compared to the traditional open repair. However, these advantages have to be weighed against the increased risk of renal dysfunction with EVAR. The evaluation of the perioperative renal function after EVAR has been hampered by the lack of sensitive and specific biochemical markers of acute kidney injury (AKI). The purpose of this study was to summarize all novel renal biomarkers and to evaluate their clinical utility for the assessment of the kidney function after EVAR. A systematic review of the current literature, as the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines, was performed to identify relevant studies with novel renal biomarkers and EVAR. Pubmed and Scopus databases were systemically searched. Studies reporting on thoracic endovascular aortic repair (TEVAR), case reports, case series, letters to the editor, and systematic reviews were excluded. Neutrophil-Gelatinase-Associated Lipocalin, Cystatin C, Liver-type fatty-acid-binding protein were the most common among the eligible studies while Interleukin-18, Retinol binding protein, N-acetyle-b-D-glucosaminidase and microalbumin have a sparse appearance in the literature. These biomarkers have been assessed in plasma as well as urine samples with each sample material having its own advantages and drawbacks. Which of these biomarkers has the most potential for assessing postoperative renal failure after EVAR, remains to be proved. The few studies presented in the literature show the potential clinical utility of these biomarkers, but larger studies with longer follow-up are required to determine the precise relationship between these biomarkers and postoperative acute kidney injury.

Meta-analysis of fenestrated endovascular aneurysm repair versus open surgical repair of juxtarenal abdominal aortic aneurysms over the last 10 years

Background

Juxtarenal abdominal aortic aneurysms pose a significant challenge whether managed endovascularly or by open surgery. Fenestrated endovascular aneurysm repair (FEVAR) is now well established, but few studies have compared it with open surgical repair (OSR). The aim of this systematic review was to compare short- and long-term outcomes of FEVAR and OSR for the management of juxtarenal aortic aneurysms.

Methods

A literature search was conducted of the Ovid Medline, EMBASE and PubMed databases. Reasons for exclusion were series with fewer than 20 patients, studies published before 2007 and those concerning ruptured aneurysms. Owing to variance in definitions, the terms 'juxta/para/suprarenal' were used; thoracoabdominal aortic aneurysms were excluded. Primary outcomes were 30-day/in-hospital mortality and renal insufficiency. Secondary outcomes included major complication rates, rate of reintervention and rates of endoleak.

Results

Twenty-seven studies were identified, involving 2974 patients. Study designs included 11 case series, 14 series within retrospective cohort studies, one case-control study and a single prospective non-randomized trial. The pooled early postoperative mortality rate following FEVAR was 3·3 (95 per cent c.i. 2·0 to 5·0) per cent, compared with 4·2 (2·9 to 5·7) per cent after OSR. After FEVAR, the rate of postoperative renal insufficiency was 16·2 (10·4 to 23·0) per cent, compared with 23·8 (15·2 to 33·6) per cent after OSR. The major early complication rate following FEVAR was 23·1 (16·8 to 30·1) per cent versus 43·5 (34·4 to 52·8) per cent after OSR. The rate of late reintervention after FEVAR was higher than that after OSR: 11·1 (6·7 to 16·4) versus 2·0 (0·6 to 4·3) per cent respectively.

Conclusion

No significant difference was noted in 30-day mortality; however, FEVAR was associated with significantly lower morbidity than OSR. Long-term durability is a concern, with far higher reintervention rates after FEVAR.

Impact of aortic wall thrombus on late changes in renal function among patients treated by fenestrated-branched endografts

OBJECTIVE

Renal function deterioration is an important determinant of mortality in patients treated for complex aortic aneurysms. We have previously determined that catheter and guidewire manipulation in diseased aortas during fenestrated-branched endovascular aneurysm repair (F-BEVAR) is associated with risk of renal function deterioration. The aim of this study was to describe the impact of atherothrombotic aortic wall thrombus (AWT) on renal function deterioration among patients treated by F-BEVAR for pararenal and extent IV thoracoabdominal aortic aneurysms.

METHODS

Clinical data of 212 patients treated for complex aortic aneurysms with F-BEVAR were entered into a prospectively maintained database (2007-2015). AWT was evaluated by computed tomography angiography using volumetric measurements in nonaneurysmal aortic segments. AWT was classified as mild, moderate, or severe using objective assessment of the number of affected segments, thrombus type, thickness, area, and circumference. Acute kidney injury (AKI) was defined using Risk, Injury, Failure, Loss of kidney function, and End-stage renal disease (RIFLE) criteria, and renal function deterioration was defined by a decline in estimated glomerular filtration rate (eGFR) >30% from baseline. Patient survival and renal outcomes were assessed at dismissal, at 6 to 8 weeks, at 6 months, and annually, including AKI, serum creatinine concentration, eGFR, chronic kidney disease stage, need for renal replacement therapy, and presence of kidney infarction.

RESULTS

There were 169 male (80%) and 43 female (20%) patients with a mean age of 75 ± 7 years. Aneurysm extent was pararenal in 157 patients and extent IV thoracoabdominal aortic aneurysm in 55 patients. A total of 700 renal-mesenteric arteries were incorporated (3.1 ± 1 vessels/patient). AWT was classified as mild in 98 patients (46%), moderate in 75 (35%), and severe in 39 (19%). At 30 days, 45 patients (21%) developed AKI. Decline in eGFR and kidney infarction were associated with higher AWT volume index and severe AWT classification (P < .05). There was no association of AWT with 30-day mortality, which was 0.5% for the entire cohort. Mean follow-up was 29 ± 23 months. Freedom from renal function deterioration was 73% ± 6% for mild, 81% ± 6% for moderate, and 66% ± 8% for severe AWT patients at 3 years (P = .012) and 46% ± 9% and 82% ± 4% for those with or without AKI after the initial procedure (P < .001). Overall, 41 patients (19%) had progression of chronic kidney disease stage, but none of the patients required renal replacement therapy. Survival was 73% ± 5% for mild, 72% ± 6% for moderate, and 69% ± 10% for severe AWT patients at 3 years (P = .67).

CONCLUSIONS

AWT is a significant predictor of AKI and continued decline in renal function after the initial F-BEVAR procedure. Longer follow-up time is needed to determine the actual impact of AWT on survival.

Stroke volume variation and serum creatinine changes during abdominal aortic aneurysm surgery: a time-integrated analysis

BACKGROUND

Patients undergoing abdominal aortic aneurysm (AAA) surgery with suprarenal clamping are at high risk for acute kidney injury (AKI) and major cardiac and cerebrovascular events (MACCE). We aimed to assess whether the stroke volume variation (SVV), a measure of hemodynamic instability, is associated with AKI in hypertensive patients undergoing elective AAA surgery with suprarenal clamping.

METHODS

In a cohort of 51 hypertensive patients, we performed serial measurements of SVV (n = 459) and serum creatinine (sCr) (n = 255). AKI was defined according to the KDIGO clinical practice guidelines. Data were analyzed by repeated-measures ANOVA and regression analysis of time-integrated changes of both SVV and sCr.

RESULTS

AKI developed in 45% of patients (stage 1: 31%; stage 2: 10%; stage 3: 2%). The diuresis during surgery (beta - 0.29 Z-score 95% [CI - 0.54, - 0.05]; p = 0.02), clamp time (beta 0.29 Z-score [0.05-0.52]; p = 0.02), and time-integrated changes in SVV from baseline to 12 h after surgery (beta 0.31 Z-score [0.03-0.60]; p = 0.03) were independent predictors of the time-integrated changes in sCr from baseline to 48 h after the end of surgery. In a model adjusted for age and sex, patients with AKI had an increased risk for MACCE during a mean follow-up of 3.5 ± 1.1 years (HR 5.53 [1.52-20.06]; p = 0.004).

CONCLUSIONS

SVV increases progressively during and after AAA surgery in subjects who will develop AKI. The increase of SVV precedes and predicts the rise in sCr and is a good discriminator of the development of AKI. AKI is associated with an increased long-term risk for MACCE.

Use of Synchrotron Radiation to Accurately Assess Cross-Sectional Area Reduction of the Aortic Branch Ostia Caused by Suprarenal Stent Wires

PURPOSE

To compare in vivo the use of synchrotron radiation to computed tomography angiography (CTA) for the measurement of cross-sectional area (CSA) reduction of the aortic branch ostia caused by suprarenal stent-graft wires.

METHODS

This study was performed with a Zenith stent-graft placed in a phantom of the human aorta to simulate treatment of abdominal aortic aneurysm. Synchrotron radiation scans were performed using beam energies between 40 and 100 keV and spatial resolution of 19.88 μm per pixel. CSA reduction of the aortic branch ostia by suprarenal stent wires was calculated based on these exposure factors and compared with measurements from CTA images acquired on a 64-row scanner with slice thicknesses of 1.0, 1.5, and 2.0 mm.

RESULTS

Images acquired with synchrotron radiation showed <10% of the CSA occupied by stent wires when a single wire crossed a renal artery ostium and <20% for 2 wires crossing a renovisceral branch ostium. The corresponding areas ranged from 24% to 25% for a single wire and from 40% to 48% for double wires crossing the branch ostia when measured on CT images. The stent wire was accurately assessed on synchrotron radiation with a diameter between 0.38±0.01 and 0.53±0.03 mm, which is close to the actual size of 0.47±0.01 mm. The wire diameter measured on CT images was greatly overestimated (1.15±0.01 to 1.57±0.02 mm).

CONCLUSION

CTA has inferior spatial resolution that hinders accurate assessment of CSA reduction. This experiment demonstrated the superiority of synchrotron radiation over CTA for more accurate assessment of aortic stent wires and CSA reduction of the aortic branch ostia.

Perioperative outcome of endovascular repair for complex abdominal aortic aneurysms

BACKGROUND

As endovascular aneurysm repair (EVAR) continues to advance, eligibility of patients with anatomically complex abdominal aortic aneurysms (AAAs) for EVAR is increasing. However, whether complex EVAR is associated with favorable outcome over conventional open repair and how outcomes compare with infrarenal EVAR remains unclear. This study examined perioperative outcomes of patients undergoing complex EVAR, focusing on differences with complex open repair and standard infrarenal EVAR.

METHODS

We identified all patients undergoing nonruptured complex EVAR, complex open repair, and infrarenal EVAR in the American College of Surgeons National Surgical Quality Improvement Program Targeted Vascular Module. Aneurysms were considered complex if the proximal extent was juxtarenal or suprarenal or when the Zenith Fenestrated endograft (Cook Medical, Bloomington, Ind) was used. Independent risks were established using multivariable logistic regression analysis.

RESULTS

Included were 4584 patients, with 411 (9.0%) undergoing complex EVAR, 395 (8.6%) undergoing complex open repair, and 3778 (82.4%) undergoing infrarenal EVAR. Perioperative mortality was 3.4% after complex EVAR, 6.6% after open repair (P = .038), and 1.5% after infrarenal EVAR (P = .005). Postoperative acute kidney injuries occurred in 2.3% of complex EVAR patients, in 9.5% of those undergoing complex open repair (P < .001), and in 0.9% of infrarenal EVAR patients (P = .007). Compared with complex EVAR, complex open repair was an independent predictor of 30-day mortality (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.1-4.4), renal function deterioration (OR, 4.8; 95% CI, 2.2-10.5), and any complication (OR, 3.7; 95% CI, 2.5-5.5). When complex vs infrarenal EVAR were compared, infrarenal EVAR was associated with favorable 30-day mortality (OR, 0.5; 95% CI, 0.2-0.9), and renal outcome (OR, 0.4; 95% CI, 0.2-0.9).

CONCLUSIONS

In this study assessing the perioperative outcomes of patients undergoing repair for anatomically complex AAAs, complex EVAR had fewer complications than complex open repair but carried a higher risk of adverse outcomes than infrarenal EVAR. Further research is warranted to determine whether the benefits of EVAR compared with open repair for complex AAA treatment are maintained during long-term follow-up.

Monocentric Evaluation of Chimney Versus Fenestrated Endovascular Aortic Repair for Juxtarenal Abdominal Aortic Aneurysm

BACKGROUND

With approval of on-label fenestrated (F-) endovascular aortic repair (EVAR), concerns regarding long-term patency and endoleaks (ELs) after chimney graft (CG)-EVAR were raised. To add supportive data on the value of this technique, we chose to report the midterm results of CG-EVAR in a single center with standardized methods and to compare them to F-EVAR.

METHODS

A retrospective analysis of prospectively gathered data from January 2010 to January 2015 was conducted, and patients with excessive comorbidities for open repair treated by CG-EVAR or F-EVAR were included.

RESULTS

Ninety patients were treated by F-EVAR (88 men, 198 targets vessels) and 31 by CG-EVAR (26 men, 39 targets vessels, 12.9% treated in emergency; P = 0.001). Mean age was significantly higher in the CG group (71.3 ± 8.2 years in the FG group vs. 75.3 ± 6.6; P = 0.02), and there were significantly more patients suffering from preoperative chronic kidney disease (CKD) (13 [14.4%] treated by F-EVAR vs. 12 [38.7%]; P = 0.009). Target vessels were successfully reconstructed in 99.0% (196/198 target vessels) vs. 97.4% (38/39 target vessels) of cases (P = 0.3). In-hospital mortality was significantly higher after CG-EVAR (3.3% vs. 16.1%; P = 0.03). Incidence of acute kidney injury and CKD did not differ significantly between both groups. At 12 and 24 months, overall survival was 91.4% after F-EVAR vs. 82.1% and 81.8% vs. 69.0% (P = 0.4), estimated freedom from aneurysm related reintervention was 93.3% vs. 82.1% and 84.9% vs. 82.1% (P = 0.6), and target vessel's primary patency rate was 97.5% vs. 89.9% (P = 0.06), respectively. Freedom from type I EL's survival was significantly higher after F-EVAR at 12 and 24 months (100% vs. 89.0% and 97.7% vs. 89.0%; P = 0.01), but aneurysm maximum transverse diameter decrease did not differ significantly.

CONCLUSIONS

There are potential advantages to CG-EVAR with off-the-shelf availability, versatility, and low-profile devices. In this series, patients treated by CG-EVAR showed promising and durable midterm results compared with F-EVAR. CG-EVAR and F-EVAR should not be apprehended as opposed strategies but more as complementary ones, while the best indications for CG-EVAR are clarified.